Web feeding for drying or like purposes



Aug. 6, 1957 w. F. HUCK WEB FEEDING FORDRYING OR LIKE PURPOSES Filed Aug. 18, 1954 MAL/AM FH UCK, INVENTOR,

inited States Patent WEB FEEDING FOR DRYING OR LIKE PURPOSES William F. Huck, New York, N. Y., assignor to Huck Co., N ew York, N. Y., a partnership Application August 18, 1954, Serial No. 450,589 6 Claims. (Cl. 271-23) This invention pertains to web or strip handling apparatus, and especially to improvements therein which permit the prolonged travel of a web or strip while one surface thereof is free of contact with rollers, guides, or the like. The invention is particularly applicable to the drying of webs or strips which have been liquid coated, printed or similarly treated, but the principles of the invention may be applied to other web handling problems as will appear hereinafter.

In many processes involving treating of webs or strips of; paper, textile material or the like, it is necessary to handle the web over extended travel distances while main taining a printed, coated or otherwise treated surface thereof out of contact with any supporting or guiding devices. During this extended travel, the web may be subjected to hot gases, radiant heat or low atmospheric pressures in order to expedite the drying or setting of materials, which have been applied to one surface thereof. It will be appreciated that in order to handle the web at reasonably high speeds, provision must be made for an extended travel distance in order that drying or setting may be substantially completed before the web or. strip is rolled up upon itself or passed to subsequent treatment stages.

Conventionally, the above aims have, been satisfied by passing the web along a horizontal path through an oven or chamber. If the travel speed is at all high, the physical length of such an oven becomes considerable, and in many cases prohibitive because of the space required; Especially, if the web is a metal strip, heat must be applied for a considerable period to raise the web temperature and this also tends to increase the oven length required.

In order to avoid the necessity for excessive horizontal length, it has also been attempted to solve the problem by utilizing a vertical oven, and allowing the coated web at pass upwardly, and over a top roller which contacts only the inner (uneoated), web surface, and then allowing the web to, descend to thebottpm of the oven. While the total oven length may be cut in half by this arrangement, the necessity for a structure of great height is equally or perhaps even more onerous. Moreover, special arrangements must be made to feed the coated web into the vertical path at theentrance to the oven unless the liquid applicator can be arranged directly below the oven axis; in this latter case, the vertical height is still further increased.

It has also been considered to provide an oven of modest maximum dimension, and to pass the web back and forth between spaced rollers to accomplish the desired total travel. Theoretically, of course, such a system would provide greater path length in a structure not requiring an excessive dimension horizontally or vertically. However, the fact that the web enters the oven in one condition of humidity, which condition may change continuously throughout the travel, requires that the web by positively driven with controlled force at diiferent locations. The control necessary to prevent excessive sag and contact of the coated side has never been accomplished 2,801,847 Patented Aug. 6, 1957 so far as is known. It will be realized that differential shrinkage or contraction during the drying processes greatly complicates the problem of tension control in such an arrangement. Any accumulation of errors in such control will rapidly make it impossible to keep the web taut enough at all points.

The present invention provides a solution to this problem, and more specifically provides web handling apparatus for use in ovens or the like, by which the maximum dimension of the equipment may be kept at a reasonable figure, and the web handled at high speed over a considerable path without any danger of one surface improperly contacting any of the guiding devices or other appurtenances. The invention accomplishes this aim by a combination of the physical relations between angularly disposed guide or support rollers, some at least of which are driven rollers, together with means for automatically and accurately controlling the tension maintained in the web between any two of its driving support elements. Fundamentally, the invention may be looked upon as an arrangement by which the suspension curve of a moving web may be accurately controlled at a large number of points spaced along its travel, while requiring support and driving contact with only one surface of said web.

The invention will best be understood by referring now to the following detailed specification of an exemplary embodiment thereof, given by way of example, and taken in connection with the appended drawings, in which:

Fig. l is a vertical sectional view of a complete apparatus embodying the invention, the same being taken along the line 1-1 of Fig. 2;

Fig. 2 is a plan view of the apparatus with the top cover and heating elements removed to clarify the path and position of the moving web; and

Fig. 3 is a fragmentary vertical sectional view taken on the line 3-3 of Fig. 2.

As best seen in Fig. 1, the web W is being unwound from a supply roll 11, which is driven on its circumference by a belt 12, passing over idle rollers 13, 14 and driven roller 15, the latter mounted upon shaft 16. The end of shaft 16 carries a variable pulley 17, connected by belt 18 and pulley 19, that is driven from the drive shaft 20.

As-the web W leaves the roll 11, it passes over lead roller 21, floating roller 22, lead roller 23, and into the coating unit 30. Floating roller .22 is supported on bellcranle 24, which fulcrums on shaft 25 at a fixed position the supporting web. roll 31 freely rotating the fountain roll; 36, being driven from the common drive shaft 29 by vertical shaft 32 and bevel gear pair 33. Fountain 37 eo tains the coating fluid (not shown) which is picked up, by the, roller 315; and applied to the web thatpasses cane t ller 32 With one side of the web now coated, it is so guided that its opposite surface only will be contacted as it passes over rollers 38 and 39 into the drying oven 40. The web passes over guide rollers 33 and 39, center roller 42 which is supported on bearings 43 riding on a common cross shaft 44 that passes through and is slidably mounted in vertical slots 45 of opposite side frames 46 and 47 so the vertical position of each end of cross shaft 44 is adjustable by the screws 48 through handwheels 49.

The web W then turns degrees about its longitudinal axis and passes around vertical roller 56 with its coated surface to the outside, whence it again turns 90 degrees back to its original plane as it passes over the next center roller 51 journalled on cr oss shaft 44. As it continues towards the left, it turns again 90 degrees to pass around the vertical roller 52, which is driven by a'variable speed belt and pulley arrangement, consisting of the fixed pulley 53 (see now Fig. 3) on the lower end of shaft 54, rotatably supported in the arm 55. The latter is fulcrumed at 56 by being pivotally supported on the bracket 57 bolted to frame 46. The opposite end of the arm 55 is urged in counterclockwise direction (Fig. 2) by the tension spring 59. A V belt 61 connects pulley 53 with variable diameter pulley 58, which is mounted on the upper end of vertical drive shaft 60. The lower end of said shaft 60 is connected by bevel gears 63 to the main shaft 29.

It will be recognized that this vertical roller 52 imparts propelling force to the web W as the latter again rotates about its axis 90 and passes over the third center roller 65 of the roller cross shaft 44.

The web now continues its path about the idle vertical roller 66, then returns to horizontal roller section 67 as it again moves left and rotates around vertical idler roller 68. It will be understood that idler roller 68 can be replaced by a driven roller such as roller 52 if required, thereby maintaining closer web tension control. As the web W now moves to the right again it passes over the last horizontal center roller 69, thence into the horizontal plane passing over the lead roller 70, downwards over lead roller 71, and to the left to pass over floating roller 72 and lead roller 73 to be rewound into roll 74.

The roll 74 is controlled by belts 75, passing over lead rollers 76, 77 and the driving roller 78. The latter is mounted on shaft 79, which has variable pulley 80 mounted thereon on the outside of the frame 47 and is drivingly connected by V belt 81 to non-variable pulley 82. The latter is supported on shaft 84, which also carries one of the bevel gear pair 85, the other being fixed to vertical shaft 86, which connects drivingly through bevel gear pair 87 to the common drive shaft 29, which in turn receives power to operate the entire machine from motor 90.

It will be noted that the center horizontal shaft 44 carrying the sectional rollers 42, 51, 65, 67 and 69 may be raised high enough so that the natural sag in the web W, which can be controlled somewhat by its tension, will cause it to lie properly around the vertical rollers 50, 52, 66, 68. It will be further understood that these vertical rollers may be somewhat inclined instead of having their axes exactly vertical. The main purpose is to have the web W supported by the center rollers on shaft 44, the latter being adjusted to a height which, in combination with the web tension control, will result in a web suspension curve that remains constant.

What is claimed is:

1. Apparatus for handling webs of material over extensive path lengths while maintaining one web surface free from contact, comprising an array of rollers including a first set of vertical axis rollers spaced horizontally from one another in one vertical plane, a second set of vertical axis rollers spaced horizontally from one another in a second vertical plane parallel to said one plane, and a set of spaced horizontal rollers mounted on a common horizontal axis passing between said vertical planes,

the upper surfaces of said horizontal rollers lying substantially above the center lines of said vertical axis rollers, the web passing in succession about a roller of one set of vertical axis rollers, thence over one of said horizontal rollers and thence about a roller of the other set of vertical axis rollers, whereby the plane occupied by the material rotates from vertical to horizontal and again to vertical in the same rotational sense as the material travels from vertical roller to succeeding vertical roller.

2. Apparatus in accordance with claim 1, including means for controlling the tension in said web at at least one intermediate point of its travel over said rollers.

3. Apparatus in accordance with claim 1, including means for adjusting the vertical height of said set of horizontal rollers as a unit with respect to the horizontal centerlines of said vertical axis rollers.

4. Apparatus for handling webs of material over extensive path lengths while maintaining one Web surface free from contact, comprising an array of rollers including a first set of vertical axis rollers spaced horizontally from one another in one vertical plane, a second set of vertical axis rollers spaced horizontally from one another in a second vertical plane parallel to said one plane, and a set of spaced horizontal rollers mounted on a common horizontal axis passing between said vertical planes, the upper surfaces of said horizontal rollers lying substantially above the horizontal center lines of said vertical axis rollers, whereby a web of material may be passed over and about said rollers to contact them in series with a single face of said material, means for feeding such a web over said horizontal rollers and about alternate rollers of said sets of vertical axis rollers, and means including a tension-sensing movable mount of at least an intermediate one of said vertical axis rollers for maintaining said web under desired tension as it passes over said rollers. I

5. Apparatus for handling a web of flexible material over an extensive total path length within restricted dimensions, while maintaining one web surface free from contact, comprising a pair of spaced-apart rollers mounted on parallel vertical axes, an intermediate roller mounted on a horizontal axis midway of the horizontal distance between the vertical rollers, means for feeding a web from one of said vertical rollers to the other with a half twist in said web to provide a horizontal orientation of the web as it passes over and in contact with the intermediate roller, and means for regulating the tension in said web between said vertical rollers so that the web drapes in a constant curve from said intermediate roller to the respective vertical rollers.

6. Apparatus in accordance with claim 5, in which said intermediate roller is mounted for adjustment of the height of its support surface above the common horizontal center line of the faces of the vertical rollers.

References Cited in the file of this patent UNITED STATES PATENTS 806,270 Lubbertsmeier- Dec. 5, 1905 1,579,657 Perrault Apr. 6, 1926 1,890,026 Barkelew Dec. 6, 1932 2,096,231 Ensign et al. Oct. 19, 1937 2,202,045 Cohn et a1. May 28, 1940 

